Act I: The Duel
Scene i
Ferrando, the captain of the guard, and his men are on guard by order of Count di Luna, who wishes to capture a troubadour who has been heard serenading the lady Leonora, for whom the Count has a deep but unrequited love. At the men’s request Ferrando tells the story of Garzia, the Count’s brother. When still a baby, Garzia was found with an old gipsy hag at his cradle. She was driven off, but the boy’s health failed and it was believed that the gipsy had bewitched him. She was captured and burnt at the stake. Her daughter, Azucena, swore revenge on her mother’s death: on the day of her execution young Garzia disappeared and the burned remains of a baby were found in the ashes of the old gypsy's funeral pyre. The old Count later died, and nothing was heard since of Azucena, although her mother’s spirit is said to have roamed the skies at night. The tale is interrupted by chiming bells.
Scene ii
Leonora tells her maid Inez how she met a mysterious knight at a tournament and fell in love with him. The knight vanished when civil war broke out. At night she has heard her troubadour singing below her window. Inez suggests that Leonora forget her lover, but the latter says she would rather die than lose him. The Count enters, declaring his burning passion for Leonora. He is about to enter her apartment when he hears a distant serenade: it is Manrico, the troubadour, who has come to woo his love. Leonora hurries to greet her lover, but mistakenly addresses the Count, and is accused of treachery by Manrico.
Act II: The Gypsy
Scene i: An encampment of gypsies
Azucena relates the story of her mother’s death and the tragic events at the pyre. Manrico asks her whether he is really her son, and she hastens to reassure him. Manrico then tells of the duel between him and the Count and how he spared his life, for he was sure he had heard a voice from heaven bidding him do this. Ruiz, a messenger from the Prince of Biscay, enters with orders for Manrico to take command of the forces defending the fortress of Castellor, and at the same time bears the news that Leonora is about to enter a convent, thinking Manrico is dead.
Scene ii
The Count plans to carry Leonora off before she takes her vows. Nuns are heard from afar as Leonora and Inez enter. Just before the Count is about to seize Leonora, Manrico stands between them and his men surround the Count. Astonished, Leonora rushes into Manrico’s arms.
Act III: The Gypsy's Son
Scene i: Count di Luna’s camp
The Count’s men are getting ready to attack Castellor. The Count himself is paining over his loss of Leonora, when Ferrando brings Azucena, who was captured while wandering near the encampment. She tries to divert attention from herself in a song, but Ferrando recognizes her as the gipsy who threw the brother of the Count into the fire. She further enrages the Count by calling for her rescue by her son Manrico, and he sentences her to be burned at the stake.
Scene ii: A room adjoining the chapel at Castellor
Leonora is preparing for her wedding to Manrico. Just as they are about to enter the altar of the chapel, Ruiz enters with news of Azucena’s capture by the Count, and of her death sentence. Manrico drops Leonora’s hand and draws his sword, leading his men to the rescue of Azucena.
Act IV: The Execution
Scene i
Manrico’s rescue plan has failed. His men have retreated, and he has been thrown into a dungeon in the palace. Leonora arrives to try and save him, wearing a ring that conceals poison. Sounds of the Miserere are heard from within the castle serving as a background to the heart-broken lament of Leonora. Manrico is in despair as he cannot save Leonora. The Count enters and Leonora promises to wed him if he frees Manrico. The Count consents, not knowing that she is planning to take the poison.
Scene ii A prison
Manrico and Azucena are awaiting their death in the tower. Azucena has a frightening vision of the death that awaits her. Manrico tries to calm her, and she finally falls asleep. Leonora hurries to tell Manrico that he is free. Manrico, suspecting her bargain with the Count, accuses her of betrayal. The poison which she has already drunk begins to take effect and she slowly sinks to her death. Count di Luna enters only to find Leonora dead in her lover’s arms. He orders the immediate death of Manrico, and summons Azucena to witness her son’s execution. As the fatal blow falls, she tells the Count that he has just killed his own brother, and finally her mother’s death has been avenged.